This section provides background information related to the present disclosure and is not necessarily prior art.
The most common form of nine-volt battery has a rectangular prism shape with rounded edges and a polarized snap connector at the top. This format is commonly available in primary carbon-zinc and alkaline chemistry, in primary lithium iron disulfide, and in rechargeable form in nickel-cadmium, nickel-metal hydride and lithium-ion.
Most nine-volt alkaline batteries are constructed of six individual 1.5V LR61 cells enclosed in a wrapper. These cells are slightly smaller than LR8D425 AAAA cells and can be used in their place for some devices, even though they are 3.5 mm shorter. Carbon-zinc types are made with six flat cells in a stack, enclosed in a moisture-resistant wrapper to prevent drying.
Lithium 9-volt batteries are consumer-replaceable, high energy density batteries designed to last up to 5 times longer than alkaline 9-volt batteries and up to 10 times longer than carbon-zinc 9-volt batteries in many applications. In addition, lithium PP3 batteries have a long shelf life of up to 10 years.
The battery has both terminals in a snap connector on one end. The smaller circular (male) terminal is positive, and the larger hexagonal or octagonal (female) terminal is the negative contact. The connectors on the battery are the same as on the connector itself; the smaller one connects to the larger one and vice versa. The same snap style connector is used on other battery types in the Power Pack (PP) series. Battery polarization is normally obvious since mechanical connection is usually only possible in one configuration. Several nine-volt batteries can be connected to each other in series to provide higher voltages.